METHOD FOR PREPARING RIBONUCLEOSIDE PHOSPHOROTHIOATE

• US 20130184450A1
• Filed: 03/04/2011
• Published: 07/18/2013
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: WAVE Life Sciences Ltd.
• Original Assignee: University of Tokyo
• Inventors: Wada, Takeshi, Nukaga, Yohei
• Granted Patent: US 8,859,755 B2
• Time in Patent Office: Days
• US Class Current: 536/26.11
• CPC Class Codes: C07H 19/06 Pyrimidine radicals
• CPC Class Codes: C07H 19/10 with the saccharide radical esterified by phosphoric or polyphosphoric acids
• CPC Class Codes: C07H 19/16 Purine radicals
• CPC Class Codes: C07H 19/20 with the saccharide radical esterified by phosphoric or polyphosphoric acids
• CPC Class Codes: C07H 21/02 with ribosyl as saccharide radical
• CPC Class Codes: Y02P 20/55 Design of synthesis routes, e.g. reducing the use of auxiliary or protecting groups

Abstract

A method for preparing a phosphorothioate RNA based on the oxazaphospholidine method, wherein cyanoethoxymethyl group is used instead of tert-butyldimethylsilyl group as a protective group of 2′-hydroxyl group of RNA.

Claims

1. A method for preparing a ribonucleoside phosphorothioate represented by the following formula (I) or a salt thereof:

2. The method according to claim 1, wherein R⁶ is a phenyl group.

3. The method according to claim 1, wherein R⁵ is a 4,4′

-dimethoxytrityl group.

4. The method according to claim 1, wherein the condensation is performed in the presence of an activator.

5. The method according to claim 4, wherein N-(cyanomethyl)pyrrolidinium triflate or N-phenylimidazolium triflate is used as the activator.

6. The method according to claim 1, wherein dimethyl thiuram disulfide is used as a sulfurizing agent.

7. The method according to claim 1, which comprises the step of repeating the aforementioned step n+1 times using a compound represented by the general formula (III) in which n is 0 as a starting material.

8. The method according to claim 1, wherein the reaction is performed by the solid phase method.

9. The method according to claim 8, wherein a compound represented by the formula (III), in which n is 0 and which is bound to a solid phase carrier optionally via a linker, is used.

10. The method according to claim 1, wherein all of n+1 of X are divalent groups represented by the formula (II-Sp), or all of them are divalent groups represented by the formula (II-Rp).

11. A ribonucleoside phosphorothioate represented by the formula (I) mentioned in claim 1, wherein, R¹, Bs, n, and X have the same meanings as those defined above, and R² represents a cyanoethoxymethyl group, or a salt thereof.

12. An oxazaphospholidine ribonucleoside represented by the formula (IVa) or (IVb) mentioned in claim 1, wherein, Bs, CEM, R⁵, and R⁶ have the same meanings as those defined above.